INTRODUCTION.

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on this intricate question : and to any person who has a practical knowledge of thelocalities themselves, I think that the following numbers (unequal as they are)will not appear to he inconsistent with the opposite dimensions and aspects of thevarious portions of the cluster to which they respectively refer. Thus, in Madeiraproper I have (up to the present period) ascertained 432 species to have occurred,in Porto Santo 111, on the Dezerta Grande 57, on the Northern Dezerta (or IlheoChao) 15, and on the Southern Dezerta (or Ilheo Bugio) 4. Or, if we choose toregard the Dezertas as one, the group will separate itself into three natural divi-sions ; and we shall have for Madeira proper 432, for the Dezertas 61 , and forPorto Santo 111. Of the 61 species which I have found on the Dezertas , 44 havebeen detected in Madeira and 29 in Porto Santo . The species which (so far as Ihave been able to ascertain) are peculiar to Madeira proper are 340, to PortoSanto 32, to the Dezerta Grande 6, to the Ilheo Chao 3, and to the Ilheo Bugio 0.

The only insects of the existence of which I have been enabled to satisfy myselffor certain on every island are the Scarites abbreviatus and the Laparocerus morio ;nevertheless I am all but convinced that the Calathus complanatus, Harpalusvividus and the Hadrus cinerascens (if we consider the H. illotus as its PortoSantan analogue) are equally universal: whilst, at the same time, they may beregarded, in conjunction with the Tarus lineatus, Bromius obscuroguttatus,Olisthopus Maderensis, Omias ventrosns, Helops Pluto and confertus, and theAnthicus tristis, as amongst the species which are the most abundant individuallyof all with which we are concerned.

Taking a cursory view of the Coleoptera here described, the fauna may perhapsbe pronounced as having a greater affinity with that of Sicily than of any othercountry which has been hitherto properly investigated. Apart from the largenumber of our genera (and even species) which are diffused over more or less ofthe entire Mediterranean basin, this is especially evinced in some of the most cha-racteristic forms,—such as Apotomus, Xenostrongylus, Tarphius, Cholovocera, Holo-paramecus, Berginus, Litargus, Thorictus and Boromorphus. There is moreover,strange though it may appear to be, some slight (though decided) collective assi-milation with what we observe in the south-western extremity of our own countryand of Ireland, '—nearly all the species which are common to Madeira and theBritish Isles being found in those particular regions; whilst one point of coin-cidence at any rate, and of a very remarkable nature, has been fully discussed(vid. p. 320) under Mesites. Whether or not this partial parallelism may beemployed to further Professor E. Forbes’s theory of the quondam approximation,by means of a continuous land, of the Kerry and Gallician hills, and of a hugemiocene continent extending beyond the Azores , and including all these Atlanticclusters within its embrace, I will not venture to suggest: nevertheless it is im-possible to deny that, so far as the Madeiras betoken, everything would go tofavour this grand and comprehensive idea. Partaking in the main of a Mediter-ranean fauna, the northern tendency of which is in the evident direction of the